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write

Write Bluetooth LE LL protocol packet data to PCAP or PCAPNG file

    Description

    write(pcapObj,packet,timestamp) writes Bluetooth® low energy (LE) link layer (LL) protocol packet data to the packet capture (PCAP) or packet capture next generation (PCAPNG) file specified in the Bluetooth LE PCAP file writer object, pcapObj. Input packet specifies the Bluetooth LE LL protocol packet, and input timestamp specifies the packet arrival time.

    example

    write(pcapObj,packet,timestamp,Name,Value) specifies options using one or more name-value pair arguments. For example, 'PacketFormat','bits' sets the format of the Bluetooth LE LL protocol packets to bits.

    Examples

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    Create a default Bluetooth LE PCAP file writer object.

    pcapObj = blePCAPWriter;

    Generate a Bluetooth LE LL packet.

    cfgLLData = bleLLDataChannelPDUConfig('LLID', ...
        'Data (start fragment/complete)');
    payload = '0E00050014010A001F004000170017000000';
    llDataPDU = bleLLDataChannelPDU(cfgLLData,payload);
    connAccessAddress = de2bi(hex2dec('E213BC42'),32)';
    llpacket = [connAccessAddress;llDataPDU];

    Write the Bluetooth LE LL packet to the PCAP file.

    timestamp = 0;                                        % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
    write(pcapObj,llpacket,timestamp,'PacketFormat','bits');

    Create a Bluetooth LE PCAPNG file writer object, specifying the name and extension of the PCAPNG file.

    pcapObj = blePCAPWriter('FileName','sampleBLELL', ...
        'FileExtension','pcapng');

    Generate a Bluetooth LE LL packet.

    cfgLLData = bleLLDataChannelPDUConfig('LLID', ...
        'Data (start fragment/complete)');
    payload = '0E00050014010A001F004000170017000000';
    llDataPDU = bleLLDataChannelPDU(cfgLLData,payload);
    connAccessAddress = de2bi(hex2dec('E213BC42'),32)';
    llpacket = [connAccessAddress; llDataPDU];

    Write the Bluetooth LE LL packet to the PCAPNG file.

    timestamp = 12800000;                               % Packet arrival time in POSIX® microseconds elapsed since 1/1/1970
    write(pcapObj,llpacket,timestamp,'PacketFormat','bits');

    Input Arguments

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    Note

    The blePCAPWriter object does not overwrite the existing PCAP or PCAPNG file. Each time when you create this object, specify a unique PCAP or PCAPNG file name.

    Bluetooth LE PCAP file writer object, specified as a blePCAPWriter object.

    Bluetooth LE LL protocol packet, specified as one of these values.

    • Binary-valued vector – This value represents bits.

    • Character vector – This value represents octets in hexadecimal format.

    • String scalar – This value represents octets in hexadecimal format.

    • Numeric vector with each element in the range [0, 255] – This value represents octets in decimal format.

    • n-by-2 character array – In this value, each row represents an octet in hexadecimal format.

    Data Types: char | string | double

    Packet arrival time in POSIX® microseconds elapsed since 1/1/1970, specified as a nonnegative integer.

    Data Types: double

    Name-Value Arguments

    Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

    Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

    Example: 'PacketFormat','bits' sets the format of the Bluetooth LE LL protocol packets to bits.

    Bluetooth LE LL protocol packet metadata, specified as the comma-separated pair consisting of PhyHeader and one of these values.

    • Binary-valued vector – This value represents bits.

    • Character vector – This value represents octets in hexadecimal format.

    • String scalar – This value represents octets in hexadecimal format.

    • Numeric vector with each element in the range [0, 255] – This value represents octets in decimal format.

    • n-by-2 character array – In this value, each row represents an octet in hexadecimal format.

    Data Types: char | string | double

    Comment for the Bluetooth LE LL protocol packet, specified as the comma-separated pair consisting of PacketComment and a character vector or a string scalar.

    Data Types: char | string

    Format of the Bluetooth LE LL protocol packet, specified as the comma-separated pair consisting of PacketFormat and 'octets' or 'bits'. If this value is specified as 'octets', packet is specified as one of these values.

    • Binary-valued vector – This value represents bits.

    • Character vector – This value represents octets in hexadecimal format.

    • String scalar – This value represents octets in hexadecimal format.

    • Numeric vector with each element in the range [0, 255] – This value represents octets in decimal format.

    • n-by-2 character array – In this value, each row represents an octet in hexadecimal format.

    Data Types: char | string | double

    Format of the physical layer (PHY) header, specified as the comma-separated pair consisting of PhyHeaderFormat and 'octets' or 'bits'. If you specify this value as 'octets', the PhyHeader argument can be specified as one of these values.

    • Binary-valued vector – This value represents bits.

    • Character vector – This value represents octets in hexadecimal format.

    • String scalar – This value represents octets in hexadecimal format.

    • Numeric vector with each element in the range [0, 255] – This value represents octets in decimal format.

    • n-by-2 character array – In this value, each row represents an octet in hexadecimal format

    Data Types: char | string | double

    References

    [1] Tuexen, M. “PCAP Next Generation (Pcapng) Capture File Format.” 2020. https://www.ietf.org/.

    [2] Group, The Tcpdump. “Tcpdump/Libpcap Public Repository.” Accessed May 20, 2020. https://www.tcpdump.org.

    [3] “Development/LibpcapFileFormat - The Wireshark Wiki.” Accessed May 20, 2020. https://www.wireshark.org.

    Extended Capabilities

    C/C++ Code Generation
    Generate C and C++ code using MATLAB® Coder™.

    Version History

    Introduced in R2020b

    See Also

    Objects